This invention relates to a structure of a power switchgear containing therein a switch and a disconnector.
FIG. 11 is a sectional side view showing the structure of a conventional switchgear. In the figure, 1 is a case body of the switchgear, 2 is a front door, 3 is a rear door, 4 are bus conductors, 5 are insulators for supporting bus conductors 4, 6 is a CT (current transformer), 7 is a connection conductor for connecting between the bus conductors 4 and the CT 6 and 8 is an interrupter in the connected state, which moves to the position shown by dashed lines on the left in the figure when drawn out. 8a are terminals for the interrupter 8, 9 is a stationary terminal supported by the insulator 10, 11 is a connection conductor connecting between the CT 6 and the stationary terminal 9, 12 is a disconnector, 13 is a connection conductor connecting the stationary terminal 9 and the disconnector 12, 14 is a cable for connecting to a load, 15 is a cable head which becomes a connection portion to the cable 14, 15a is a field moderation metal disposed at the top portion of the cable head 15 and 16 is a connection conductor for connection the disconnector 12 and the cable head 15. Also, this switchgear is partitioned into a bus bar compartment 17 for housing the bus conductors 4, an interrupter compartment 18 for housing the interrupter 8, a disconnector compartment 19 for housing the disconnector 12, a cable compartment for housing the cable 14 and a controller compartment positioned behind the front door.
The conventional switchgear which has the above-described structure has its main circuit current path of substantially U-shape and the total length is long, so that a predetermined insulating space must be maintained around the main circuit, and since the main circuit is long and contains many connection portions, a large heat generates during the operation, so that a large case body was needed. Therefore, the shipping efficiency to the install site is low and the electric chamber in which the switchgear is to be installed must be large.
Accordingly, the present invention has been made in order to solve the above problems of the conventional switchgear and has as its object the provision of a disconnector unit that is compact and short in the main circuit length and small in heat generation.
With the above objects in view, the present invention resides in a switchgear comprising: a first stationary terminal and a second stationary terminal disposed in pair on a main circuit extending from a bus conductor to a cable to separate the main circuit; a switch disposed between said first stationary terminal and said second stationary terminal for switching on and off said main circuit; and a disconnector capable of contacting with or separating from said first stationary terminal or said second stationary terminal for switching on and off said main circuit.
The present invention also resides in a switchgear comprising: a first stationary terminal and a second stationary terminal disposed in pair on a main circuit extending from a bus conductor to a cable to separate the main circuit; a draw out type switch capable of contacting with or separating from one of said first stationary terminal and said second stationary terminal between said first stationary terminal and said second stationary terminal for switching on and off said main circuit; and a disconnector capable of causing its movable contact to contact with or separate from the other of said first stationary terminal and said second stationary terminal for switching on and off said main circuit.
The first stationary terminal and said second stationary terminal may be disconnecting portion terminals which contact with and separate from the main circuit terminal of the draw out type switch.
The switchgear of the present invention may comprise: a cable compartment; a bus conductor compartment for housing bus conductors arranged at the upper portion of a cable compartment with their back faces in alignment; an interrupter compartment disposed at the boundary portion between said bus conductor compartment and said cable compartment to intrude from the front; an upper insulating partition wall disposed in the upper half portion of said interrupter compartment for defining a partition between said bus conductor compartment and having a penetration hole through which the terminal of said interrupter can be pass; a lower insulating partition wall disposed in the lower half portion of said interrupter compartment for defining a partition between said cable compartment and having a window through which the terminal of said interrupter can be pass; a first stationary terminal and a second stationary terminal for contacting with or separating from the switch arranged on the bus conductor compartment side and the cable compartment side of said upper insulating partition wall and said lower insulating partition wall; and a disconnector of which movable contact is capable of contacting with and separating from said first stationary terminal and said second stationary terminal.
A cable head may be disposed at the tip of the cable raised from the below, the movable contact of the disconnector may be mounted to the top portion of the cable head and said movable contact may be capable of contacting with or separating from the first stationary terminal and the second stationary terminal.
The electrical insulating plate may be disposed at the side portion of the contacting portion between said first stationary terminal and the second stationary terminal and the movable contact of the disconnector to provide a partition with respective to the neighboring phases and the ground.
A cable head may be disposed at the tip of the cable raised from the below, the movable contact of the disconnector may be mounted to the top portion of the cable head and said movable contact of said disconnector may be operable into three positions of a connected position in which it is connected to the first stationary terminal or the second stationary terminal, a disconnected position in which it is separated by a predetermined distance from the first stationary terminal or the second stationary terminal and a grounded position in which it is connected to the grounding terminal.